There are no cheats for any Pokemon game unless you have an action replay.
The fisherman in Olivine will give it to you. His house is in the center of town.
Without a gameshark, there is one or two cheats for Pokemon yellow Including the rare but good glitch which is called walk through walls without a game shark. you should look it up on the internet
I agree with Karateboy (I am a big fan of Pokemon cystal and i say that either pidgeot or noctowl are the best) but I think farfetche'd, Ho-oh or Lugia
well, just go to Google and type in "pokemon pearl cheats"
gameshark codes will be found for it on gaameshark.com or gamewinners.com i have cool codes to encounter celibi in the wild, but sadly my gameshark codes did not save :[ p.s. you spelt Pokemon crystal wrong you put cristal it is crystal by the way you should check out seribi.net for game walkthroughs
Suicune, Raikou, and Entei
Buy an action replay. You can find one at a very good price at most best buy stores. There is no way to cheat unless you have a gameshark or AR that is legal.
shout Pokemon at the screen. i hate the person that put this probaly
There aren't any. And that's a good thing. Cheats ruin games like Pokemon. If you count it, I suppose an Action Replay is a device that allows cheating. But you have to pay, which is good.
If you have a PokeRadar in your game, you can use it to get rare, shiny, and high leveled Pokemon. If you really want to use cheats you should get an action replay.
cheatsguru.com/pc/pokemon_indigo has all sorts of good cheats and they have the shiny cheat
Go to ign.com or neoeeker.com they are really good websites for cheats i hope i helped. :-)